Press Releases

Yorba Linda, CA - (September 25, 2007) - Spirent Federal Systems announced today that they have delivered the first SDS M-code simulation systems to Raytheon, El Segundo, and Rockwell Collins, Cedar Rapids, in support of their Modernized User Equipment (MUE) Receiver Card Development contracts with the Global Positioning Systems (GPS) Wing. The Spirent GSS7700 series GPS simulator has a fully approved classified package, integrated interference/jamming signal generation, Advanced Encryption Standard (AES) M-code and Simulator Data Sets (SDS) M-code capabilities that already received the Global Positioning Systems Wing security approval in June 2007. President Ellen Hall stated, "We are proud to be the first company to deliver an SDS M-code simulator for use on the important MUE contract."

The SDS M-code simulators that Spirent Federal delivered include a new SDS server unit and an advanced GSS7700 signal generator. The SDS server provides storage for the SDS files, processes streams of data from the SDS files in real-time, and transmits the SDS data to the GSS7700 signal generator. The GSS7700 signal generator integrates the SDS data with all other simulated signals to produce integrated RF output. The new SDS capabilities are fully integrated into Spirent's comprehensive, user-friendly SimGEN user interface, and they operate simultaneously with all of the other capabilities of the GSS770 simulator. Spirent Federal's Director of Engineering, Jim Holderle, says "Spirent's GSS7700 provides a complete GPS testing solution, with all of the capabilities specified by the GPS Wing for modernized Precise Positioning Service (PPS) simulators, including all SDS simulator functions."

With over twenty years experience in providing GPS simulators, Spirent has cost effective solutions for all satellite navigation test requirements and applications. Dedicated customer support and a commitment to ongoing product enhancement have ensured Spirent Federal's position as the leading supplier of GPS simulators.

For further information, contact Spirent Federal at (714) 692-6565 or visit the company's website at www.spirentfederal.com).

About Spirent Federal Systems
Spirent Federal Systems was formed in July 2001 by Spirent Communications as a wholly owned subsidiary and U.S. proxy company. Spirent Federal markets and sells Spirent Communications' products in North America. The company also provides value-added features and ongoing customer support. Spirent Federal Systems is headquartered in Yorba Linda, Calif., with support and sales offices throughout the US.

About Spirent Communications plc
Spirent Communications (www.spirent.com) is a global provider of integrated performance analysis and service assurance systems that enable the development and deployment of next-generation networking technology such as Internet telephony, broadband services, 3G wireless, global navigation satellite systems, and network security equipment. Spirent Communications' solutions are used by more than 1,700 customers in 30 countries, including the world's largest equipment manufacturers, service providers, enterprises and governments. Based in Sunnyvale, CA, Spirent Communications has 1,500 employees worldwide.

Spirent Communications plc Ordinary shares are traded on the London Stock Exchange (ticker: SPT). The Company operates a Level 1 American Depositary Receipt ("ADR") programme with each ADR representing four Spirent Communications plc Ordinary shares. The ADRs trade in the US over-the-counter ("OTC") market under the symbol SPMYY and the CUSIP number is 84856M209. Spirent Communications' sales to the United States government are made through Spirent Federal Systems Inc (www.spirentfederal.com).

Spirent, Spirent Communications and the Spirent logo are trademarks or registered trademarks of Spirent Communications plc. All other trademarks or registered trademarks mentioned herein are held by their respective companies. All rights reserved.

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